not 100% sure on the front with 2.5. I would say there isn't a need. The rear seems to have problems with welds breaking so it is a good idea to do it even if it leaves your axle off center a little bit. I have yet to see the front break. I think your geometry should be good at 2.5" the way it is without the bracket.
Are you having any DW or bump steer problems now?
If not, I think I would recomend just getting the rear.
YOu could ask somebody that has one how much it raises the trackbar mounting point and then you would be able to see how it would look. It is nice to have the trackbar closer to lhorizontal and it will raise the roll center. With that said, the track bar and draglink need to be parrallel with each other for proper steering geometry. The trick is to not look at the bars themselves but at thye mounting points and draw an imaginary line between them. TAke a look at your rig as all lifts are different. Detirmine where the draglink would be sitting flipped. Then youwil have a good idea if the bars will be parrallel if you used the bracket.
I know the rear bracket moves the mounting point up about 4"s. I would guess that the front moves the mounting point up the same distance as the draglink flip moves the draglink up but I have never seen the measurments on the poly one